Another thing to consider is that Carbonite throttles the hell out of your connection so that you're only able to upload at the following speeds:

* The first 35GB of data can achieve upload speeds of up to 2 mbps (megabits per second).

* Between 35GB - 200GB of data can have the upload speeds reach up to 512 kbps (kilobits per second).

* 200GB or more of data can be uploaded at up to 100 kbps (kilobits per second).

So if you use Carbonite to backup over 200GB of data, and let's say your computer is on for 6 hours a day, you can only backup 270MB a day which is useless (or 1.08GB if you run your computer 24 hours a day). I did the math and it would take 1 year 7 months for me to backup the 800GB of data I wanted to with Carbonite.

It's also not fair to compare Carbonite to Dropbox. Comparing Carbonite to Mozy would be a more leveled playing field.